Mississippi Embayment Region

Appropriately located in the most southern and bottomland section of The Arboretum is The Mississippi Embayment (aka Jackson Purchase).  It is one of the smaller regions on The Walk Across Kentucky, but equally as engaging and floristically rich.  Here, you might find some species that do not occur anywhere else in the state.   To name a few, parsley hawthorn, water tupelo, Nuttall oak, water locust, Water elm, and water hickory.  As these names imply, water and wet soils are an absolute must.

As it so happens, we had water (specifically stormwater) in spades here.  The amount of runoff was so extensive that in 2006 The Mississippi Embayment was awarded a grant to build a constructed wetland.  This area, the Mississippi Embayment Wetland exhibit, is now a visitor favorite that includes the long boardwalk, island, and ephemeral pool.  Not only did the project correct flooding problems in the adjacent neighborhood, but it provided the ideal location to cultivate the many obligate wetland species in a functionally aesthetic way.  This exhibit has year round interest as has become an important habitat for ducks, hawks, turtles, and more.

From ‘The Big Picture: Ecological Regions of Kentucky’ by Dr. Julian Campbell:

 “This flattest region of Kentucky is part of the northern extension of the Gulf Coastal Plain that extends from Florida to Texas.  It lies on gravels, sands, silts, and clays deposited by the Mississippi River and its major tributaries during the ‘relatively’ – for Kentucky – recent eras: Cretaceous (65-135 million years old), Tertiary (2-65 million), and Quaternary (less than 2 million including ice ages). 

The region is mostly made up of high terraces (plains) and gently rolling hills.  It also contains extensive bottomlands along the central Mississippi River.  More hilly uplands occur on acid Cretaceous gravels to the east, including much of Land-Between-the-Lakes, and on the more fertile ‘loess bluffs’ to the west.  Loess is dust that was blown from dry river valleys during ice ages, and in this part of Kentucky its deposits are up to 80 feet thick.  It forms a narrow band of hills that extends along much of the Mississippi River from Kentucky to the Gulf.

There is a surprising variety of native forested and open habitats.  The extensive swamps and other wetlands include many southern species near their northern limits, including much bald cypress and water tupelo on the wettest ground.”